When a project I'm leading is behind schedule, I address the situation by first identifying the reasons for the delay. I then prioritize tasks and reallocate resources if necessary to get the project back on track. Additionally, I communicate transparently with stakeholders about the delay and the steps being taken to mitigate it. By adjusting timelines, delegating tasks effectively, and fostering a collaborative team environment, I strive to bring the project back on schedule while maintaining quality and stakeholder satisfaction.